INSTALLATION, OPERATION AND MAINTENANCE MANUAL – COSA 9610™
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adjusted based on the application.
After this throttle back the output of the analyzer flow to 40 liter/hr (660 CCM or 1.4
CFH) using the needle valve on flow meter tagged "Analyzer flow".
3.1.6. Adjusting booster relays
Set the chosen residual O
2
set point with help of the booster relay. With the
booster relay it is possible to give a small negative (i.e., the gas pressure is higher
than the air pressure) or positive offset of max 0.5 bar, as set point correction or as
pressure drop compensation over the air- and gas tubes in the heat exchanger.
To change the offset pressure, remove a plug on the top the top of the booster
relay. Using a screwdriver slowly turn CCW until a decent negative offset is reached.
In other words, the air pressure is lowered in comparison with the gas
pressure. The correct choice of a negative rather than a positive offset needs to be
used for proper analyzer operation. The chosen residual oxygen concentration,
combined with the average of the chosen range of measurement, gives according to
these curves the selection of the air nozzle and an indication for the booster offset.
!
Caution
The adjusting screw is located in the gas compartment of the relay. When the plug
is released, gas will escape. Be prepared before the relay is going to be adjusted,
e.g., have the right equipment readily available, so the gas compartment must be
open for only a minimum of time.
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